I'd eliminate the dining plan.
I would add awesome child swaps for all thrill rides. Disney could learn from Universal on this one. And the child swaps would have movies or small play areas while people wait.
I would add more splash pads, misters, etc for people to keep cool. Disney lacks on this compared to other parks.
Speaking of splash pads, I would add those and maybe more tunnel play areas for kids. The type of things that you don't have to wait in line for and the kids can burn off some steam.
I'd add another dessert wishes party area. It's wonderful to sit down and eat during fireworks, but it's SO hard to get a reservation.
I would keep the FP return time set (where you can't come back late), but I would extend it to 2 hours.
I would add a job where CMs just make a little magic happen in some form or another. Living here, we have had so many little things happen (my son getting almost a whole roll of stickers, a free ice cream bar when he dropped his, etc). But it doesn't happen every visit. I would like to see the magic happen more often to people. Not so much for us, but for all the people who come to visit on vacation.
I would add the same soda fountain systems they use at the water parks to all other parks. They still get their money for the drinks, but people can get their own. I've noticed lines for those are significantly smaller. Then people wouldn't get over heated waiting for drinks.
I would limit stroller and
ECV use to those truely in need.
I would update Epcot's future world.
And since I am dreaming, I would add more thrill rides, or open a another park with them. We live here and have AP's to Disney, US, and Sea World/BG. Disney is my fav because of the magic and theming. My older kids and DH love US, SW, and BG due to the thrill rides. Not that Disney is hurting for business, but they are missing out by not having enough.